Reagent splitting/dispensing method based on reagent dispensing nozzle and reagent splitting/dispensing mechanism

ABSTRACT

A reagent splitting/dispensing method based on a reagent dispensing nozzle controls a split or dispensation amount of reagent, includes a waiting process of disposing a first air layer between an interface of the operation fluid and a nozzle tip end in the reagent dispensing nozzle; a first moving process of moving the reagent dispensing nozzle to a position above the reagent to be split; a second moving process of depositing the nozzle tip end in the reagent; an air layer adjusting process of increasing the occupation amount of the operation fluid in the reagent dispensing nozzle and decreasing the occupation amount of the first air layer, between the first moving process and the second moving process; and a reagent splitting process of decreasing the occupation amount of the operation fluid in the reagent dispensing nozzle and filling the reagent into the reagent dispensing nozzle from the nozzle tip end.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation application of U.S. application Ser.No. 13/009,037, filed Jan. 19, 2011, the contents of which areincorporated herein by reference.

BACKGROUND

1. Field of the Invention

The present invention relates to a mechanism that splits/dispenses atrace amount of a liquid (micro order), and more particularly, to amethod that splits/dispenses a reagent by a reagent dispensing nozzle ina luminescence measuring device and a mechanism thereof.

2. Description of the Related Art

In various clinical medicine sites, food factories, medicinal drugmanufacturing factories, and basic research sites, an aseptic workenvironment and predetermined biological cleanliness are required. In anenvironment where the biological cleanliness is required, the number ofmicroorganisms (the number of viable bacteria) in the air (floatingbacteria in the air), the number of falling bacteria, and the number ofadhesive bacteria are measured. As a method that measures the number offloating bacteria in the air, it is general to use a sampler of thefloating bacteria in the air to collect the floating bacteria by naturalfalling of the floating bacteria or sucking air of a constant amount incollecting the floating bacteria.

In this method, the floating bacteria are collected on an agar plate andare cultured by an incubator for two or three days, and the number ofcolonies generated after culturing is used as the number of bacteria.However, in this method, a long time is needed to culture the viablebacteria.

Meanwhile, as a method that enables measurement of the number ofmicroorganisms in a short time, a method that measures adenosinetriphosphate (ATP) corresponding to a component in a cell by abioluminescence method and converts the number of microorganisms isknown.

In the bioluminescence method, a luciferin-luciferase luminescencereaction is used, the ATP amount is calculated from the luminescenceamount of light generated by mixing and reacting a luminescence reagentcontaining substrate luciferin and enzyme luciferase and a samplesolution containing the ATP extracted from the cells of themicroorganisms, and the number of viable bacteria is calculated on thebasis of the ATP amount per viable bacterium. In Japanese PatentApplication Laid-Open (JP-A) No. 11-155597, a kit that measures thenumber of viable bacteria using the luminescence reaction is disclosed.

According to the method that measures the number of viable bacteriausing the kit disclosed in JP-A No. 11-155597, a measurement time can bedecreased. However, when the viable bacteria of the minute amount aremeasured, the luminescence amount becomes the minute amount. For thisreason, background luminescence is greatly affected by mixing of theremaining ATP or the ATP other than the measurement object, and superiormeasurement precision cannot be obtained.

Meanwhile, in JP-A No. 2008-249628, a luminescence measuring device thatcan suppress background luminescence due to viable bacteria adhered to anozzle to dispense a reagent or a remaining ATP and can quickly measureluminescence with high precision is disclosed.

According to the luminescence measuring device that is disclosed in JP-ANo. 2008-249628, even in luminescence measurement where the viablebacteria of the minute amount are measured, it is assumed that theviable bacteria of the minute amount can be quickly measured with highprecision. However, when the viable bacteria of the minute amount aremeasured by the luminescence measuring device, a measurement value maybe greatly affected by contamination in the device.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide asplitting/dispensing method based on a reagent dispensing nozzle and areagent splitting/dispensing mechanism that can prevent contamination ofan operation fluid in the reagent dispensing nozzle to split/dispense areagent when the reagent dispensing nozzle is in a waiting state orgeneration of cross contamination due to falling of a droplet when thereagent dispensing nozzle is moved, and split/dispense the reagent withhigh precision.

To solve the aforementioned problem to be solved by the invention, thereagent splitting/dispensing method based on a reagent dispensing nozzlethat controls a split amount or a dispensation amount of a reagent by anoperation fluid disposed in the reagent dispensing nozzle, the reagentsplitting/dispensing method is featured by including the following: awaiting process of disposing a first air layer between an interface ofthe operation fluid and a nozzle tip end in the reagent dispensingnozzle; a first moving process of moving the reagent dispensing nozzleto the position right above the reagent becoming a split object; asecond moving process of depositing the nozzle tip end in the reagent; areagent splitting process of decreasing the occupation amount of theoperation fluid in the reagent dispensing nozzle and filling the reagentinto the reagent dispensing nozzle from the nozzle tip end; a thirdmoving process of evacuating the tip end of the reagent dispensingnozzle from the reagent; a reagent protecting process of disposing asecond air layer between an interface of the split reagent and thenozzle tip end; a fourth moving process of moving the reagent dispensingnozzle to the reagent dispensation position, after the reagentprotecting process; a reagent dispensing process of increasing theoccupation amount of the operation fluid in the reagent dispensingnozzle and ejecting the split reagent; an operation fluid protectingprocess of disposing the first air layer between the interface of theoperation fluid and the nozzle tip end, after dispensing the reagent;and a fifth moving process of evacuating the reagent dispensing nozzleto the waiting position, in a state where the first air layer isdisposed between the interface of the operation fluid and the nozzle tipend.

Also, the reagent splitting/dispensing method having the aforementionedcharacteristic features preferably includes the following steps: an airlayer adjusting process of increasing the occupation amount of theoperation fluid in the reagent dispensing nozzle and decreasing theoccupation amount of the first air layer, between the first movingprocess and the second moving process. By using these processes, whenthe reagent is filled into the reagent dispensing nozzle, the capacityof the first air layer that is disposed between the reagent and theinterface of the operation fluid can be decreased. Thereby, thesplitting/dispensing error of the reagent due to the compression orexpansion of the air layer can be decreased.

Also, the reagent splitting/dispensing method having the aforementionedcharacteristic may includes the following: a temporary evacuatingprocess of moving the reagent dispensing nozzle to the operation fluiddischarge position after the reagent dispensing process; and anoperation fluid ejecting process of ejecting a part of the operationfluid from the nozzle tip end, at the operation fluid dischargeposition. By using these processes, the operation fluid that exists nearthe interface where the possibility of the reagent being mixed orcontaminated is high can be discharged. Thereby, generation of the crosscontamination of the reagent or the contamination of the reagent can beprevented.

Further, in the reagent splitting/dispensing method having theaforementioned characteristics, it is preferable that, in the reagentdispensing process, the process proceeds to the temporary evacuatingprocess, after the first air layer remains. By adopting these units, thereagent that is filled into the reagent dispensing nozzle can becompletely ejected, and the operation fluid in the reagent filled nozzlecan be prevented from being ejected.

Also, in order to solve the aforementioned problems to be solved by theinvention, the reagent splitting/dispensing mechanism according to anexemplary embodiment of the invention includes a triaxial actuator inwhich a movement axis in a horizontal direction is set to an X axis anda Y axis and a movement axis in a vertical direction is set to a Z axis,a reagent dispensing nozzle which is moved by the triaxial actuator, anda pump unit which is connected to the reagent dispensing nozzle ancontrols an operation fluid disposed in the reagent dispensing nozzle.The reagent splitting/dispensing mechanism is featured by including: acontrol unit which outputs a first air layer arrangement signal todecrease the occupation amount of the operation fluid in the nozzle anddispose a first air layer between an interface of the operation fluidand a nozzle tip end in the reagent dispensing nozzle to the pump unit,outputs a first movement signal to move the reagent dispensing nozzle tothe position right above the reagent becoming a split object and asecond movement signal to deposit the nozzle tip end in the reagent tothe triaxial actuator after the first air layer is disposed in thereagent dispensing nozzle, outputs a reagent split signal to decreasethe occupation amount of the operation fluid in the nozzle and fill thereagent into the reagent dispensing nozzle from the nozzle tip end tothe pump unit after the nozzle tip end is deposited in the reagent,outputs a third movement signal to evacuate the tip end of the reagentdispensing nozzle from the reagent to the triaxial actuator, outputs areagent protection signal to dispose a second air layer between aninterface of the split reagent and the nozzle tip end to the pump unit,outputs a fourth movement signal to move the reagent dispensing nozzleto the reagent dispensation position to the triaxial actuator, after thesecond air layer is disposed in the reagent dispensing nozzle, outputs areagent dispensation signal to increase the occupation amount of theoperation fluid in the reagent dispensing nozzle and eject the reagentto the pump unit, after the reagent dispensing nozzle reaches thereagent dispensation position, outputs an operation fluid protectionsignal to decrease the occupation amount of the operation fluid in thereagent dispensing nozzle and dispose the first air layer between theinterface of the operation fluid and the nozzle tip end to the pumpunit, after the reagent is ejected from the reagent dispensing nozzle,and outputs a fifth movement signal to evacuate the reagent dispensingnozzle where the first air layer is disposed after the reagent isdispensed to the waiting position to the triaxial actuator.

Also, in the reagent splitting/dispensing mechanism having theaforementioned characteristic features, the control unit outputs an airlayer adjustment signal to increase the occupation amount of theoperation fluid in the reagent dispensing nozzle to the pump unit,between the output of the first movement signal and the output of thesecond movement signal. By using the control unit having the aboveconfiguration, when the reagent is filled into the reagent dispensingnozzle, the capacity of the first air layer that is disposed between thereagent and the interface of the operation fluid can be decreased.Thereby, the splitting/dispensing error of the reagent due to thecompression or expansion of the air layer can be decreased.

In the reagent splitting/dispensing mechanism having the aforementionedcharacteristic features, it is preferable that the control unit outputsa temporary evacuation signal to move the reagent dispensing nozzle tothe operation fluid discharge position to the triaxial actuator, afterthe reagent dispensation signal is output, and the control unit outputsan operation fluid ejection signal to increase the occupation amount ofthe operation fluid in the reagent dispensing nozzle to eject a part ofthe operation fluid from the tip end of the reagent dispensing nozzlemoved to the operation fluid discharge position, to the pump unit. Byusing the control unit having the above configuration, the operationfluid that exists near the interface where the possibility of thereagent being mixed or contaminated is high can be discharged. Thereby,generation of the cross contamination of the reagent in the reagentdispensing nozzle or the contamination of the reagent can be prevented.

In the reagent splitting/dispensing mechanism having the aforementionedcharacteristic features, the reagent dispensation signal is a signal tocontrol the occupation amount of the operation fluid to completely ejectthe reagent filled into the reagent dispensing nozzle and eject a partof the first air layer. By adopting these units, the reagent that isfilled into the reagent dispensing nozzle can be completely ejected, andthe operation fluid in the reagent filled nozzle can be prevented frombeing ejected.

In the reagent splitting/dispensing mechanism that has the abovecharacteristics, the pump unit is preferably configured as a syringepump. By using this configuration, the reagent can be split/dispensedwith high precision.

According to the reagent splitting/dispensing method by use of a reagentsplitting nozzle having the above characteristics, when the reagentdispensing nozzle to split/dispense the reagent is in awaiting state,contamination of the operation fluid in the reagent dispensing nozzleand falling of the droplet can be prevented. Thereby, generation of thecross contamination can be prevented and the reagent can besplit/dispensed with high precision.

According to the reagent splitting/dispensing mechanism having the abovecharacteristics, the method is executed and an effect based on themethod can be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing the configuration of a luminescencemeasuring device;

FIG. 2 is a schematic view showing the lateral configuration of ameasuring unit;

FIG. 3A is a front block diagram showing a relationship between theschematic configuration of a triaxial actuator and a reagent dispensingnozzle;

FIG. 3B is a top block diagram showing a relationship between theschematic configuration of a triaxial actuator and a reagent dispensingnozzle;

FIG. 4 is a reference perspective view showing a relationship between aZ-axis mechanism unit, a fixed block, and the reagent dispensing nozzle;

FIG. 5A is a top view showing the configuration of a reagent/carriercontainer mounting unit;

FIG. 5B is a top view showing a reagent cartridge;

FIG. 6 is a flow view showing an aspect of luminescence measurementbased on a luminescence measuring device;

FIGS. 7A to 7G are diagrams showing a state where the reagent issplit/dispensed using the reagent splitting/dispensing mechanismaccording to an exemplary embodiment of the invention; and

FIG. 8 is a flowchart showing each operation process in the reagentsplitting/dispensing mechanism.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, an embodiment of a reagent splitting/dispensing methodbased on a reagent dispensing nozzle and a reagent splitting/dispensingmechanism according to the present invention will be described in detailwith reference to the drawings.

First, the entire configuration of a luminescence measuring device(biomedical device) 10 that mounts a reagent splitting/dispensingmechanism according to this embodiment will be described with referenceto FIG. 1. The luminescence measuring device 10 that is described inthis embodiment includes a measuring unit 12 and a collecting unit 80.

The measuring unit 12 has a reagent dispensing unit 14, a hot watersupply unit 42, a reagent/carrier container mounting unit 54, a buffersupply unit 64, a filter unit 72, a photomultiplier tube (PMT) unit 78,and an input/control unit (hereinafter, simply called control unit 11).These components are disposed in an outer shell.

The reagent dispensing unit 14 is configured using a triaxial actuator16, a reagent dispensing nozzle 24, and a syringe pump (pump unit) 32 asa basic body. The triaxial actuator 16 is a unit to move the reagentdispensing nozzle to be described in detail below to the desiredposition. For this reason, the triaxial actuator 16 includes a Y-axismechanism unit 18, an X-axis mechanism unit 20, and a Z-axis mechanismunit 22 to be described in detail below. The Y-axis mechanism unit 18 isdisposed on a device that is rarely spatially restricted. For thisreason, in the measuring unit 12 according to this embodiment, astepping motor 18 a is used as a driving actuator and a movable unit 18c that is attached to a linear guide 18 b is slid by a driving belt 18d.

Meanwhile, the X-axis mechanism unit 20 and the Z-axis mechanism unit 22attached to the movable unit 18 c are difficult to have a spatialmargin. For this reason, in the X-axis mechanism unit 20 and the Z-axismechanism unit 22, a compact actuator is adopted. The compact actuatoris a small actuator that is configured by incorporating a thrust axissystem having a large diameter in a hollow rotor and integrating a motorand a protrusion shaft with each other. As a driving principle, adriving system is set as the stepping motor and the protrusion shaft isset as a ball screw. For this reason, positioning with high precision isrealized while a size is decreased.

The reagent dispensing nozzle 24 is a nozzle that splits/dispensesvarious reagents used in luminescence measurement by the desired amount.As shown in FIGS. 3A, 3B, and 4, the reagent dispensing nozzle 24 issupported by a fixing block 28 that is included in a slide guide 26attached to the compact actuator corresponding to the Z-axis mechanismunit 22. By adopting this support form, an elevating operation can bestabilized.

FIG. 3A is a front block diagram showing a relationship between theschematic configuration of the triaxial actuator 16 and the reagentdispensing nozzle 24. FIG. 3B is a block diagram showing theconfiguration of a top surface in FIG. 3A. FIG. 4 is a referenceperspective view showing a relationship between the Z-axis mechanismunit 22 and the reagent dispensing nozzle 24.

To a rear end of the reagent dispensing nozzle 24, a dispensingoperation tube 30 that is connected to the syringe pump 32 to bedescribed in detail below is connected. The reagent dispensing nozzle 24splits the reagent by applying the negative pressure to an inner part ofthe nozzle through the dispensing operation tube 30 and dispenses thesplit reagent by applying the positive pressure to the inner part of thenozzle. The reagent dispensing nozzle 24 may be composed of a resin ormetallic tube, in addition to a glass tube.

The syringe pump 32 performs a control operation of an operation fluid(pure water in this embodiment) to split/dispense the reagent by thereagent dispensing nozzle 24. The syringe pump 32 is configured using asyringe 34, a plunger 36, and an actuator 38 as a basic body. Thesyringe 34 is a tank that stores the pure water corresponding to theoperation fluid. The plunger 36 is a pushing rod that applies thenegative pressure or the positive pressure to the inner part of thesyringe 34 to introduce the pure water into the syringe 34 and dischargethe pure water from the syringe 34. The actuator 38 is a driving unitthat pushes in or pulls out the plunger 36. If the stepping motor andthe ball screw are used in the actuator 38, position control with highprecision is enabled.

To a tip end of the syringe 34 in the syringe pump 32 having the aboveconfiguration, one end of the dispensing operation tube 30 is connected.The other end of the dispensing operation tube 30 is connected to thereagent dispensing nozzle 24 described above. By connecting thedispensing operation tube 30 in the above-described way, the pure wateris collected by pulling out the plunger 36 and the reagent is injected(split) into the reagent dispensing nozzle 24. In contrast, when theplunger 36 is pushed therein, the power water that is discharged fromthe inner part of the syringe 34 is moved to the reagent dispensingnozzle 24. For this reason, the pressure in the reagent dispensingnozzle 24 increases and the reagent that is collected in the reagentdispensing nozzle 24 is ejected (dispensed).

To the dispensing operation tube 30, the buffer supply tube 70 that isconnected to the buffer supply unit 64 to be described in detail belowis connected through a distribution valve 40 such as a three-way valve.By this configuration, the pure water that is the operation fluidcollected in the dispensing operation tube 30 can be regularly switched.Thereby, an error of measurement data can be suppressed from beinggenerated due to contamination of the operation fluid.

The hot water supply unit 42 supplies pure water to dilute a collectioncarrier. The hot water supply unit 42 is configured using a peristalticpump 44, a heater 46, and a hot water supply nozzle 48 as a basic body.The peristaltic pump 44 is configured using a resin tube, a resinroller, and an actuator as a basic body (none of them are shown in thedrawings). The resin tube is a tube that is used to send a solution anda conveyance fluid (pure water in this embodiment) flows through theresin tube. The resin tube is preferably configured to have flexibilityand durability, because the resin tube may be crushed by a roller. Forexample, the resin tube may be composed of a silicon tube. The rollerrepeats the rotation and the revolution while crushing the resin tubeand extrudes the conveyance fluid closed in a crushing region to arevolution direction of the roller. In the resin tube that is crushed bythe roller, the power that causes a shape of the resin tube to return toan original shape works. Since the conveyance fluid is a non-compressionfluid, even though plural rollers continuously revolve and extrude theconveyance fluid, the operation is continuously performed. Any actuatorthat can rotate the plural rollers may be used.

According to the peristaltic pump 44 having the above configuration,since a place contacting the conveyance fluid (pure water in thisembodiment) is only an inner part of the tube where the conveyance fluidflows, the bump is not contaminated. For this reason, an aseptic statecan be easily maintained and cleaning can be easily performed.

The heater 46 heats the pure water that is the conveyance fluid. Theconfiguration of the heater 46 is not particularly limited. However,when the heater 46 needs to be configured to have a small size, acartridge heater or a tube heater is preferably adopted. For example,when the cartridge heater is adopted, a metallic tube 46 b may bewounded around the outer circumference of a heater body 46 a and thepure water corresponding to the conveyance fluid may be circulated inthe wound metallic tube 46 b. This is because the pure water in themetallic tube 46 b is heated by heat transmission, if the aboveconfiguration is used. When the tube heater is adopted, a rubber heateris wound around the resin tube (tube) and the conveyance fluid that iscirculated in the resin tube is heated. In this configuration, if thesilicon resin is used in the resin tube, a heat transfer coefficient isincreased. Since the resin tube and the rubber heat are configured tohave the flexibility, a degree of freedom of arrangement is high and aheated region can be secured to be long. For this reason, thetemperature after heating can be avoided from being lowered, that is,the temperature can be stabilized. The arrangement position of theheater 46 is not particularly limited. However, it is preferable todecrease the solution sending distance after the heating to prevent thetemperature after the heating from being lowered. Therefore, in themeasuring unit 12 according to this embodiment, the heater 46 isdisposed between the peristaltic pump 44 and the hot water supply nozzle48 to be described in detail below.

The hot water supply nozzle 48 is an ejection nozzle that supplies thehot water (pure water), which is sent by the peristaltic pump 44 andheated by the heater 46, to the collection carrier cartridge 82 to bedisposed in the reagent/carrier container mounting unit 54 to bedescribed in detail below. The hot water supply nozzle 48 may beconfigured using a metal (SUS) tube. Alternatively, the hot water supplynozzle 48 may be configured using a glass tube or a resin tube. To anend at the side opposite to an ejection port in the hot water supplynozzle 48, the hot water supply tube 50 that is connected to peristalticpump 44 through the heater 46 is connected. A suction-side tube 52 inthe peristaltic pump 44 is connected to the buffer supply unit 64 to bedescribed in detail below.

According to the hot water supply unit 42 having the aboveconfiguration, the hot water can be continuously ejected from the hotwater supply nozzle 48, by driving the peristaltic pump 44.

The reagent/carrier container mounting unit 54 is a stage to dispose thereagent or the collection carrier used in the luminescence measurement.In the reagent/carrier container mounting unit 54, a collection carriercartridge holder 56, a reagent rack 58, a luminescence measuring tubeholder 60 a, and a water discharge port 100 are disposed. The collectioncarrier cartridge holder 56 is a holder to set the collection carriercartridge 82. The collection carrier cartridge holder 56 is providedwith a heat block including a heater and heats the set collectioncarrier cartridge 82.

In the reagent rack 58, a reagent cartridge where the reagent used inthe luminescence measurement is filled is disposed. As shown in FIGS. 5Aand 5B, the reagent cartridge is a package where reagents of differentkinds and pure water are filled into concave parts (9 parts in anexample shown in FIG. 5B) partitioned in plural parts. An upper openingof each concave part is sealed by an aluminum sheet (film). By thisconfiguration, the reagent is not exposed to the outside, until thealuminum sheet is removed, and the reagent that is placed in stock isnot contaminated by viable bacteria. FIG. 5A is a top view of thereagent/carrier container mounting unit 54 and FIG. 5B is a top view ofthe reagent cartridge 62.

In the luminescence measuring tube holder 60 a, a luminescence measuringtube 60 is disposed. The luminescence measuring tube 60 is a micro tubethat executes a luminescence reaction of the ATP extracted from theviable bacteria collected by the collection carrier cartridge 82.

The water discharge port 100 is a disposable port to discard the purewater corresponding to the operation fluid of the reagent dispensingnozzle 24 or the pure water from the hot water supply nozzle 48. Thewater discharge port 100 has an operation fluid discharge position 102to discharge the operation fluid from the reagent dispensing nozzle 24and a hot water discharge position 104 to discharge the hot water fromthe hot water supply nozzle 48. By regularly or periodically dischargingthe pure water collected in the nozzle, generation of the bacteria inthe nozzle and contamination of the nozzle can be prevented. Further, anincrease of the contamination in the device or generation of crosscontamination can be prevented.

The buffer supply unit 64 has a reagent dispensing nozzle control watertank (hereinafter, simply referred to as control water tank 66) and ahot water supply water tank 68. In a process after the reagentdispensing nozzle 24 is used, since a process of removing isolated ATPis not included, the water (pure water) in the control water tank 66that is filled into the dispensing operation tube 30 to link the syringebump 32 and the reagent dispensing nozzle 24 needs to have cleannesshigher than the water (pure water) in the hot water supply water tank68. For this reason, the control water tank 66 is configured to have asmall capacity and appropriately exchange the stored water, as comparedwith the hot water supply tank 68. Since the water in the hot watersupply water tank 68 flows into the collection carrier cartridge 82 setto the collection carrier cartridge holder 56, the hot water supplywater tank 68 needs to have the large capacity, as compared with thecollection carrier cartridge holder 56.

The control water tank 66 that is set in the above-described way isconnected to the distribution valve 40 in the dispensing operation tube30 by the buffer supply tube 70, and the pure water can be supplied tothe dispensing operation tube 30 by switching the distribution valve 40.The hot water supply water tank 68 is connected to the suction side ofthe peristaltic pump 44 and is sucked by driving the peristaltic pump44.

The filter unit 72 removes the collection carrier in the collectioncarrier cartridge 82 that is diluted by the hot water ejected from thehot water supply nozzle 74. The filter unit 72 is configured using asuction pump 74 and a suction head 76 as a basic body. The suction pump74 is a pump that generates the negative pressure in the suction head 76to be described in detail below. The suction head 76 is a tubular bodywhere a front end is opened.

In the filter unit 72 that has the above configuration, a tip end isconnected to a lower part of the collection carrier cartridge holder 56,and the collection carrier that is diluted by the hot water can besucked and removed through a collection filter 90 (refer to FIG. 6) byoperating the suction pump 74.

A PMT unit 78 measures the luminescence amount of the ATP in theluminescence measuring tube 60. In the measuring unit 12 according tothis embodiment, the PMT unit 78 is configured in a head-on type and isdisposed on the lower part of the luminescence measuring tube 60. Bythis configuration, the light that is generated in the luminescencemeasuring tube 60 is incident from an upper part of the PMT unit 78 andthe luminescence amount is measured.

The control unit 11 is an element that controls the components withrespect to the input value to the luminescence measuring device andautomates the luminescence measurement.

The collecting unit 80 is a device that collects the viable bacteria inthe air in the collection carrier cartridge 82. The collecting unit 80is configured using a collection carrier cartridge 82, a blast fan 84,an impactor nozzle head 86, and a discharge filter 88 as a basic body.

The collection carrier cartridge 82 collects the viable bacteria thatfloat in the air. The collection carrier cartridge 82 includes acollection carrier 82 a (refer to FIG. 6) to collect the viablebacteria. The collection carrier 82 that is included in the collectioncarrier cartridge 82 according to this embodiment forms a gel shape atthe normal temperature and is solated by heating. In a lower part of thecollection carrier 82 a, a cavity (not shown) to fill diluting hot wateris provided. A lower part of the cavity includes a collection filter 90(refer to FIG. 6) that filters the hot water diluting the collectioncarrier 82 a.

The blast fan 84 sucks air in the collecting unit 80 and collides thecollecting carrier 82 a in the collection carrier cartridge 82 with thefloating bacteria in the air. The blast fan 84 is preferably disposed onthe downstream side (lower part side to use an upper part as a suctionport in the collecting unit 80 according to this embodiment) of thearrangement position of the collection carrier cartridge 82. In thecollecting unit 80, the amount of air to be collected can be determinedfrom the blast amount of the blast fan 84 and the operation time.

The impactor nozzle head 86 is disposed on an upper part of thecollecting unit 80 and functions as a cover and an accelerator of thecollection carrier cartridge 82. In order to collide the collectioncarrier cartridge 82 with the viable bacteria, the flow velocity of theair that flows into the collecting unit 80 needs to be fast to somedegree. However, the blast fan 84 needs to be formed to have a largesize or have a high rotation speed to obtain the high flow velocity, anda size of the collecting unit may be increased.

In the impactor nozzle head 86, plural ports with the small diameter areprovided, and the air that is sucked by the blast fan 84 passes throughthe ports with the small diameter and collide the collection carrier 82a. When the flow volume of the air is constant, the flow velocity of thepassed fluid can be increased by narrowing an area of a flow passage.For this reason, the needed flow velocity can be obtained withoutincreasing the size or the rotation speed of the blast fan 84.

The discharge filter 88 is disposed on the downstream side (lower sidein the collecting unit 80 in this embodiment) of the blast fan 84 andremoves dust that is contained in the discharged air.

By this configuration, the collecting unit 80 according to thisembodiment can have a small size and light weight.

In the luminescence measuring device 10 with the above configurationthat includes the measuring unit 12 and the collecting unit 80, first,the viable bacteria in the air are collected by the collecting unit 80(step 100: refer to FIG. 6).

Next, the collection carrier cartridge 82 where the viable bacteria arecollected is extracted from the collecting unit 80 and the collectingunit 80 is set to the collection carrier cartridge holder 56 of themeasuring unit 12. The collection carrier cartridge 82 that is set tothe collection carrier cartridge holder 56 is heated by the heat block.By the heating, the collection carrier is solated. The solatedcollection carrier 82 a is sucked and removed by the filter unit 72through the collection filter 90, and the viable bacteria and the freeATP that are collected in the collection carrier 82 a remain in thecollection filter (step 110: refer to FIG. 6).

After the collection carrier 82 a is filtered, the free ATP is removedand a viable bacteria sample is split by operating the reagentdispensing unit 14. First, the (ATP removal) reagent is split from thereagent cartridge 62 by the reagent dispensing nozzle 24, the reagent isdispensed to the collection carrier cartridge 82, and the free ATP isremoved. By this work, the measurement error of the luminescence amountcan be prevented from being generated due to the luminescence reactioncaused by the free ATP. Next, the (ATP extraction) reagent is dispensedon the collection filter 90 in the collection carrier cartridge 82 afterthe free ATP is removed, and the ATP is extracted from the viablebacteria on the collection filter 90 (step 120: refer to FIG. 6).

The ATP extraction sample is split from the collection filter 90 in thecollection carrier cartridge 82 and is dispensed to the luminescencemeasuring tube 60. In the luminescence measuring tube 60, theluminescence reagent is dispensed in advance, and the luminescencereaction starts at the same time as the dispensing of the ATP extractionsample. In the luminescence reaction in the luminescence measuring tube60, the luminescence strength is measured by the PMP unit 78 (step 130:refer to FIG. 6).

In the luminescence measuring device 10 that has the aboveconfiguration, the process from the splitting of the viable bacteriasample from the collection carrier cartridge 82 to the measurement ofthe luminescence amount is automatically executed in the measuring unit12 that is covered with the outer shell. For this reason, the viablebacteria sample is rarely affected by the contamination. After theluminescence reagent is previously dispensed to the luminescencemeasuring tube 60 set to the reagent/carrier container mounting unit 54,the ATP extraction sample from the viable bacteria is dispensed. Forthis reason, self background light of the reagent can be measured. Forthis reason, a relationship between the luminescence amount and theluminescence time can be accurately obtained, and calculation of the ATPamount based on the luminescence amount, that is, measurement of thenumber of viable bacteria can be performed with high precision.

Next, the reagent splitting/dispensing mechanism according to thisembodiment will be described with reference to FIGS. 7 and 8. FIGS. 7Ato 7G are state views showing an aspect of reagent splitting/dispensingbased on the reagent dispensing nozzle in the measuring unit. FIG. 8 isa flowchart showing each operation of the reagent splitting/dispensingmechanism. The reagent splitting/dispensing mechanism according to thisembodiment is configured to include the reagent dispensing unit 14 andthe control unit 11. In the reagent splitting/dispensing mechanism thathas the above configuration, the reagent is split/dispensed as follows.

The reagent splitting/dispensing operation based on the reagentdispensing nozzle 24 is executed on the basis of a drive signal from thecontrol unit 11 with respect to various actuators. First, in a statewhere the reagent dispensing nozzle 24 is at the waiting position, thecontrol unit 11 outputs a drive signal (first air layer arrangementsignal) to pull out the plunger 36 and generate the negative pressure inthe syringe 34 to the actuator 38 of the syringe pump 32. The actuator38 receives the first air layer arrangement signal and is driven. As aresult, the pure water that is the operation fluid filled into thedispensing operation tube 30 and the reagent dispensing nozzle 24 flowsinto the syringe 34 of which the pressure becomes the negative pressure.Thereby, an occupied area of the operation fluid in the reagentdispensing nozzle 24 is decreased, and a first air layer 110 is disposedbetween an interface of the operation fluid and a nozzle tip end in thereagent dispensing nozzle 24. By disposing the first air layer 110 inthe nozzle tip end, the operation fluid is prevented from verticallyfalling from the nozzle tip end in the waiting state. For this reason,generation of the cross contamination due to falling of a droplet ordeterioration of splitting/dispensing precision due to the change in thereagent concentration can be prevented.

The first air layer 110 that is disposed in the waiting processpreferably secures the sufficient capacity with respect to the volume ofthe reagent dispensing nozzle 24. In this case, the sufficient capacitymay be a ratio of about 30 to 120% of the nozzle capacity. When thenozzle capacity is set as 20 pi, the capacity of the first air layer 110may be set as 100 pi (refer to FIG. 7A: step 200: waiting process).

Next, the control unit 11 outputs a drive signal (first drive signal) tomove the reagent dispensing nozzle 24 to the position right above theconcave part where the reagent becoming the splitting object in thereagent cartridge 62 is filled, to the X-axis mechanism unit 20 and theY-axis mechanism unit 18 in the triaxial actuator 16. In the waitingprocess described above, since the air layer (first air layer 110)having the sufficient capacity with respect to the volume of the reagentdispensing nozzle 24 is disposed in the tip end of the reagentdispensing nozzle 24, the operation fluid does not fall at the time ofmoving as well as waiting (step 210: first moving process).

Next, the control unit 11 outputs a drive signal (air layer adjustmentsignal) to push the plunger 36 and to generate the positive pressure inthe syringe 34 to the actuator 38 of the syringe 32. The actuator 38receives the air layer adjustment signal and is driven. As a result, theoperation fluid is discharged from the syringe 34 of which the pressurebecomes the positive pressure, and the operation fluid flows into thereagent dispensing nozzle 24 through the dispensing operation tube 30.Thereby, an occupied area of the operation fluid in the reagentdispensing nozzle 24 is increased. In this case, the air layeradjustment signal drives the actuator 38, such that a part of the firstair layer 110 is discharged from the reagent dispensing nozzle 24 andthe other part remains in the tip end of the reagent dispensing nozzle24. That is, the air layer adjustment signal causes the movement amountof the plunger 36 based on the air layer adjustment signal to besmaller, as compared with the first air layer arrangement signal (referto FIG. 7B: step 220: air layer adjusting process).

Next, the control unit 11 outputs a drive signal (second movementsignal) to descend the reagent dispensing nozzle 24 and deposit thenozzle tip end in the reagent to the Z-axis mechanism unit 22 in thetriaxial actuator 16 (step 230: second moving process).

Next, the control unit 11 outputs a drive signal (reagent split signal)to pull out the plunger 36 and generate the negative pressure in thesyringe 34 to the actuator 38 of the syringe pump 32. The actuator 38receives the reagent split signal and is driven. As a result, theoperation fluid that is filled into the dispensing operation tube 30 andthe reagent dispensing nozzle 24 flows into the syringe 34 of which thepressure becomes the negative pressure. Thereby, an occupied area of theoperation fluid in the reagent dispensing nozzle 24 is decreased and thereagent that becomes the splitting object flows from the tip end of thereagent dispensing nozzle 24. By this operation, the first air layer 110is interposed between the operation fluid and the reagent. Thereby, theoperation fluid is not mixed with the reagent and generation of thecross contamination due to mixing and diffusing of the reagent ordeterioration of dispensation precision of the reagent can be prevented(refer to FIG. 7C: step 240: reagent splitting process).

Next, the control unit 11 outputs a drive signal (third movement signal)to ascend the reagent dispensing nozzle 24 and evacuate the nozzle tipend from the reagent to the Z-axis mechanism unit 22 in the triaxialactuator (step 250: third moving process).

Next, the control unit 11 outputs a drive signal (reagent protectionsignal) to pull out the plunger 36 and output generate the negativepressure in the syringe 34 to the actuator 38 of the syringe pump 32.The actuator 38 receives the reagent protection signal and is driven. Asa result, the operation fluid that is filled into the dispensingoperation tube 30 and the reagent dispensing nozzle 24 flows into thesyringe 34 of which the pressure becomes the negative pressure. Thereby,an occupied area of the operation fluid in the reagent dispensing nozzle24 is decreased and the second air layer 112 is disposed between theinterface of the reagent disposed in the tip end of the reagentdispensing nozzle 24 and the nozzle tip end. Thereby, dispensationprecision can be prevented from being deteriorated due to verticalfalling of a droplet of the reagent with respect to the nozzle tip endand the cross contamination can be prevented from being generated due tofalling of the droplet (refer to FIG. 7D: step 260: reagent protectingprocess).

Next, the control unit 11 outputs a drive signal (fourth movementsignal) to move the reagent dispensing nozzle 24 to the reagentdispensation position to the X-axis mechanism unit 20 and the Y-axismechanism unit 18 in the triaxial actuator 16. In this case, the reagentdispensation position means an upper part of the collection carriercartridge holder 56 or an upper part of the luminescence measuring tube60 (step 270: fourth moving process).

Next, the control unit 11 outputs a drive signal (reagent dispensationsignal) to push the plunger 36 into the actuator 38 of the syringe pump32 and to cause the positive pressure to be generated in the syringe 34.The actuator 38 receives the reagent dispensation signal and is driven.As a result, the operation fluid is discharged from the syringe 34 ofwhich the pressure becomes the positive pressure, and the operationfluid flows into the reagent dispensing nozzle 24 through the dispensingoperation tube 30. Thereby, an occupied area of the operation fluid inthe reagent dispensing nozzle 24 is increased. In this case, the reagentdispensation signal drives the actuator 38, such that the reagent filledinto the reagent dispensing nozzle is ejected and a part of the firstair layer 110 remains in the tip end of the reagent dispensing nozzle.By this operation, the split reagent can be completely dispensed and theoperation fluid can be prevented from being ejected (refer to FIG. 7E:step 280: reagent dispensing process).

Next, the control unit 11 outputs a drive signal (temporary evacuationsignal) to move the reagent dispensing nozzle 24 to the operation fluiddischarge position 102 in the water discharge port 100 to the X-axismechanism unit 20 and the Y-axis mechanism unit 18 in the triaxialactuator 16 (step 290: temporary evacuating process).

Next, the control unit 11 outputs a drive signal (operation fluidejection signal) to push the plunger 36 into the actuator 38 of thesyringe 32 and to cause the positive pressure to be generated in thesyringe 34. The actuator 38 receives the operation fluid ejection signaland is driven. As a result, the operation fluid is discharged from thesyringe 34 of which the pressure becomes the positive pressure, and theoperation fluid flows into the reagent dispensing nozzle 24 through thedispensing operation tube 30. The amount of flowing operation fluidexceeds the allowed amount of the nozzle and a part of the operationfluid is ejected to the operation fluid discharge position 102. Theoperation fluid of the ejected amount is replenished from the controlwater tank 66 by controlling the distribution valve 40 disposed in thedispensing operation tube 30 and operating the actuator 38 to pull outthe plunger 36 (refer to FIG. 7F: step 300: operation fluid ejectingprocess).

Next, the control unit 11 outputs a drive signal (operation fluidprotection signal) to pull out the plunger 36 and generate the negativepressure in the syringe 34 to the actuator 38 of the syringe pump 32.The actuator 38 receives the operation fluid protection signal and isdriven. As a result, the operation fluid that is filled into thedispensing operation tube 30 and the reagent dispensing nozzle 24 flowsinto the syringe of which the pressure becomes the negative pressure.Thereby, an occupied area of the operation fluid in the reagentdispensing nozzle 24 is decreased and the first air layer 110 isdisposed between the interface of the operation fluid filled into thereagent dispensing nozzle 24 and the nozzle tip end. In this case, thedisposed first air layer 110 is set to have the same capacity as that ofthe first air layer 110 disposed in the waiting process described above(refer to FIG. 7G: step 310: operation fluid protecting process).

Next, the control unit 11 outputs a drive signal (fifth movement signal)to move the reagent dispensing nozzle 24 to the waiting position to theX-axis mechanism unit 20 and the Y-axis mechanism unit 18 in thetriaxial actuator 16 (step 320: fifth moving process).

When the reagent is dispensed again after the fifth moving process ends,the repetitive control from the first moving process (step 210) isexecuted.

According to the reagent splitting/dispensing mechanism where the abovecontrol is performed under the above configuration, when the reagentdispensing nozzle 24 to split/dispense the reagent is in the waitingstate, the operation fluid in the reagent dispensing nozzle 24 can besuppressed from being contaminated. The droplet can be prevented fromfalling at the time of the movement operation, and the crosscontamination can be prevented from being generated. Thereby, thereagent splitting/dispensing operation can be performed with highprecision.

What is claimed is:
 1. A reagent splitting/dispensing method based on areagent dispensing nozzle that controls a split amount or a dispensationamount of a reagent by an operation fluid disposed in the reagentdispensing nozzle, the reagent splitting/dispensing method comprising: awaiting process of disposing a first air layer between an interface ofthe operation fluid and a nozzle tip end in the reagent dispensingnozzle; a first moving process of moving the reagent dispensing nozzleto a position above the reagent to be split; a second moving process ofdepositing the nozzle tip end in the reagent; an air layer adjustingprocess of increasing the occupation amount of the operation fluid inthe reagent dispensing nozzle and decreasing the occupation amount ofthe first air layer, between the first moving process and the secondmoving process; a reagent splitting process of decreasing the occupationamount of the operation fluid in the reagent dispensing nozzle andfilling the reagent into the reagent dispensing nozzle from the nozzletip end.
 2. The reagent splitting/dispensing mechanism comprising: atriaxial actuator in which a movement axis in a horizontal direction isset to an X axis and a Y axis and a movement axis in a verticaldirection is set to a Z axis; a reagent dispensing nozzle which is movedby the triaxial actuator; a pump unit which is connected to the reagentdispensing nozzle and controls an operation fluid disposed in thereagent dispensing nozzle; and a control unit which outputs a first airlayer arrangement signal to decrease the occupation amount of theoperation fluid in the nozzle and dispose a first air layer between aninterface of the operation fluid and a nozzle tip end in the reagentdispensing nozzle to the pump unit, outputs a first movement signal tomove the reagent dispensing nozzle to a position above the reagent to besplit and a second movement signal to deposit the nozzle tip end in thereagent to the triaxial actuator after the first air layer is disposedin the reagent dispensing nozzle, outputs an air layer adjustment signalto increase the occupation amount of the operation fluid in the reagentdispensing nozzle to the pump unit, between the output of the firstmovement signal and the output of the second movement signal, outputs areagent split signal to decrease the occupation amount of the operationfluid in the nozzle and fill the reagent into the reagent dispensingnozzle from the nozzle tip end to the pump unit after the nozzle tip endis deposited in the reagent.